M68K: INT32_MIN displacement triggers signed overflow in printer

[carrerasdarren-cell]

Work environment

Questions	Answers
System Capstone runs on OS/arch/bits	macOS arm64 and Linux arm64, 64-bit
Capstone module affected	M68K
Source of Capstone	git clone
Version/git commit	251c5bb4bc9bb92973e738ae3c5f4ef86f103356 on next

Expected behavior

M68K base and memory-indirect displacements with the value INT32_MIN should format as -$80000000 without undefined behavior.

Actual behavior

The printer passes a signed 32-bit INT32_MIN displacement to abs(). Negating that value cannot be represented by int, and UBSan reports signed overflow in M68KInstPrinter.c.

This is also the root cause of public OSS-Fuzz issue 484248078, reported as a MemorySanitizer use-of-uninitialized-value in printAddressingMode.

Steps to reproduce the behavior

Build next with -DENABLE_ASAN=ON, then disassemble either input in M68K-040 mode:

47 f1 21 30 80 00 00 00
20 f0 ff ff 80 00 00 00 80 00 00 00

For example:

UBSAN_OPTIONS=halt_on_error=1 ./cstool m68k40 '20 f0 ff ff 80 00 00 00 80 00 00 00'

The expected output is:

move.l ([-$80000000], -$80000000), (a0)+

[carrerasdarren-cell]

Closing as duplicate of #2990. That earlier contribution identified the same signed-overflow root and has already been revised toward the maintainer-requested shared formatting helper.